Unlike Atticus and Calpurnia, Harper Lee does not give us a paragraph describing Jem. Instead we must learn about his character through his actions and speech. Sometimes Scout will use a descriptive sentence for her brother's character but mostly the reader learns about him as the story progresses. Many of Jem's statements in the first chapter are written in the imperative mood. For example, he says, "Don't blame me when he gouges your eyes out." By using the imperative mood, Harper Lee shows Jem to be older and seemingly the leader of Dill and Scout. The use of the indicative mood in Jem's dialogue also shows his stubbornness as a leader. When Dill is pressuring him into touching the house of Boo Radley, Jem says, "I'm going...don't hurry me." Even though Jem is worried about what may happen when he touches the house, he stays in control of the situation by using both the indicative and imperative mood in this sentence. Jem is also seen as the protector of Scout. When Jem is hesitant about making Boo Radley come out of the house because he fears for his life, Scout notes, "Besides, Jem had his little sister to think of." It is clear from this sentence, that Jem looks out for Scout which shows that he is a protective, responsible older brother.
I'm not 1000% confident in this answer but I believe it's B) to inform readers about the tactics Sparta and Rome used to hold cities and their effectiveness
